Multiple chamber airbag system

BACKGROUND

p-0002The present disclosure relates generally to the field of airbag use in motor vehicles. More specifically, this disclosure relates to a multiple chamber airbag having different pressures in each chamber to optimize restraint forces on the occupant to mitigate occupant injury.

p-0003Airbags are located in vehicles to protect occupants from injury during a vehicle dynamic impact event, which triggers sensors located in the vehicle to initiate deployment of an airbag(s). An airbag may deploy and inflate, by gas rapidly-entering its cushion(s) or chamber(s), typically through the use of an inflator containing an explosive charge (e.g., pyrotechnic device). Passenger airbags are typically stored within and deployed from the passenger dashboard compartment, and are typically packaged through a process of folding and rolling to compact the airbag in order to minimize its required packaging space. During a vehicle dynamic impact event, a passenger airbag deploys, typically from the upper portion (i.e., above the glove box) of the dashboard, in substantially rearward and upward directions to protect the head and torso of the occupant.

p-0004It has been known to construct a vehicle to include a passenger airbag <b>60</b> which may be mounted on the top facing surface of the dashboard, as shown in <figref idrefs="DRAWINGS">FIG. 3</figref>, or on the rear facing surface of the dashboard, as shown in <figref idrefs="DRAWINGS">FIG. 4</figref>. The airbag <b>60</b> may be constructed having a single chamber whereby the gas generated by the inflator is directly forced into the airbag chamber, unfolding and expanding the airbag chamber to provide protection to the vehicle occupant during a vehicle impact. It has also been known to construct a bi-lobular airbag, which includes a single chamber airbag having two adjacent lobes separated by a gap or void, whereby each lobe is directly inflated by the inflator. These methods of construction have several disadvantages, the key disadvantage being that during deployment of the airbag, each chamber or lobe will have substantially similar expansion forces, therefore exerting substantially uniform restraint forces onto all areas of contact with the occupant.

p-0005It would be advantageous for an airbag to be constructed to include of multiple chambers, whereby each chamber may exert a different predetermined restraint force onto the occupant, thereby mitigating occupant injury by optimizing restraint forces (i.e., having lower restraint forces on the lower mass head and neck regions, while having higher restraint forces on the higher mass chest or torso region). This configuration would provide optimized occupant protection and reduce head and neck injuries.

SUMMARY

p-0006One embodiment of this disclosure relates to an airbag for use within a motor vehicle, which includes a gas generator for supplying inflation gas; a lower chamber configured to be inflated directly by the gas generator; an upper chamber located above and proximate to the lower chamber; and a diffusing panel configured to separate the lower and upper chambers and allows inflation gas to pass through. The upper chamber is to be indirectly inflated by the gas generator through the diffusing panel, and upon completed deployment will have an internal pressure lower than the deployed internal pressure of the lower chamber. The airbag may further include a housing for storing the folded airbag and the gas generator, and at least one tether to provide stability during deployment of the airbag, which may be configured in a substantially vertical direction extending from the lower portion of the lower chamber to the lower portion of the upper chamber. The diffusing panel may includes a plurality of apertures or may be constructed of a porous material to allow gas flow to pass through.

p-0007Another embodiment of this disclosure relates to an inflatable safety device for use within a motor vehicle, which includes an airbag having a lower chamber coupled to an upper chamber by a diffusing panel; and a gas generator to provide inflation gas to the airbag. The lower chamber is configured to be inflated directly by the gas generator, and the upper chamber, having an internal pressure lower than the internal pressure of the lower chamber, is indirectly inflated by the gas generator through the diffusing means of the diffusing panel. The diffusing panel is configured to separate the lower and upper chambers, having a diffusing means to allow a predetermined gas flow to pass through. The diffusing means may include a plurality of apertures to allow gas flow to pass through, or the diffusing panel may be constructed of a porous material to allow gas flow to pass through. The inflatable safety device further includes a housing for storing the folded airbag and the gas generator, and at least one tether to provide stability during deployment of the airbag, which may be configured in a substantially vertical direction extending from the lower portion of the lower chamber to the lower portion of the upper chamber.

BRIEF DESCRIPTION

p-0008<figref idrefs="DRAWINGS">FIG. 1</figref> is a perspective view of an exemplary embodiment of a motor vehicle.

p-0009<figref idrefs="DRAWINGS">FIG. 2</figref> is a perspective view of an exemplary embodiment of an interior passenger compartment of a motor vehicle, such as the motor vehicle of <figref idrefs="DRAWINGS">FIG. 1</figref>.

p-0010<figref idrefs="DRAWINGS">FIG. 3</figref> is a cross-car section view of an interior passenger compartment, such as the passenger compartment of <figref idrefs="DRAWINGS">FIG. 2</figref>, illustrating a conventional embodiment of a single chamber airbag in the unfolded (deployed) state.

p-0011<figref idrefs="DRAWINGS">FIG. 4</figref> is a cross-car section view of another embodiment of a single chamber airbag in the unfolded (deployed) state.

p-0012<figref idrefs="DRAWINGS">FIG. 5</figref> is a cross-car section view of the interior passenger compartment of <figref idrefs="DRAWINGS">FIG. 2</figref> according to an exemplary embodiment of a multiple chamber airbag shown in the folded (undeployed) state.

p-0013<figref idrefs="DRAWINGS">FIG. 6</figref> is a cross-car section view of the interior passenger compartment of <figref idrefs="DRAWINGS">FIG. 2</figref> according to an exemplary embodiment of a multiple chamber airbag shown in the unfolded (deployed) state.

p-0014<figref idrefs="DRAWINGS">FIG. 7</figref> is a cross-car section view of another exemplary embodiment of a multiple chamber airbag shown in the unfolded (deployed) state.

p-0015<figref idrefs="DRAWINGS">FIG. 8</figref> is a cross-car section view of another exemplary embodiment of a multiple chamber airbag shown in the unfolded (deployed) state.

p-0016<figref idrefs="DRAWINGS">FIG. 9</figref> is a detail view of an exemplary embodiment of a gas routing for use within a multiple chamber airbag, such as the multiple chamber airbag of <figref idrefs="DRAWINGS">FIG. 8</figref>.

p-0017<figref idrefs="DRAWINGS">FIG. 10</figref> is a detail view of another exemplary embodiment of a gas routing for use within a multiple chamber airbag.

p-0018<figref idrefs="DRAWINGS">FIG. 11</figref> is a cross-car section view of another exemplary embodiment of a multiple chamber airbag shown in the unfolded (deployed) state.

p-0019<figref idrefs="DRAWINGS">FIG. 12</figref> is a cross-car section view of another exemplary embodiment of a multiple chamber airbag shown in the unfolded (deployed) state.

p-0020<figref idrefs="DRAWINGS">FIG. 13</figref> is a perspective view of another exemplary embodiment of a multiple chamber airbag shown in the unfolded (deployed) state.

DETAILED DESCRIPTION

p-0021Referring generally to the FIGURES, disclosed are multiple chamber airbags for use within a motor vehicle, configured to provide improved occupant protection by optimizing the restraint forces that are exerted onto the occupant during deployment. A multiple chamber airbag, in accordance with the present disclosure, can offer improved occupant protection by having multiple chambers, each having a tailored chamber pressure (during deployment), to control the restraint forces exerted by each chamber onto its specific region of contact with the occupant. Additionally, the disclosed multiple chamber airbags may have a reduced mass and cost, resulting from the use of a lower mass (and cost) inflator, since the volume of direct inflation may be reduced.

p-0022According to an exemplary embodiment, a multiple chamber airbag system includes an upper chamber, a lower chamber, a center panel, and an inflator. The lower chamber may be directly inflated by the inflator, thereby having a higher chamber pressure, and may support the torso of the occupant during deployment. The upper chamber may support the head and neck of the occupant and may be indirectly inflated by the inflator, thereby having a lower internal chamber pressure relative to the internal chamber pressure of the lower chamber, during deployment. The center panel separates the upper and lower chambers and allows gas to pass from the lower chamber into the upper chamber.

p-0023According to another exemplary embodiment, a multiple chamber airbag system includes an upper chamber, a lower chamber, a center panel, an inflator, and at least one tether. The lower chamber may be directly inflated by the inflator, thereby having a higher chamber pressure, and may support the torso of the occupant during deployment. The upper chamber may support the head and neck of the occupant, and may be indirectly inflated by the inflator, thereby having a lower internal chamber pressure relative to the internal chamber pressure of the lower chamber, during deployment. The center panel separates the upper and lower chambers and allows gas to pass from the lower chamber into the upper chamber. The airbag may be constructed to include tethers to improve the deployment trajectory or shape, further improving occupant protection.

p-0024According to another exemplary embodiment, a multiple chamber airbag system includes an upper chamber, a lower chamber, a center panel to separate the upper and lower chambers, an inflator, and an airbag ring. The lower chamber and the upper chamber may be directly inflated by the inflator, through the airbag ring. The airbag ring controls the amount of gas that enters each chamber, thereby during deployment, the upper chamber may have a lower internal chamber pressure relative to the internal chamber pressure of the lower chamber.

p-0025According to another exemplary embodiment, a multiple chamber airbag system includes an upper chamber, a lower chamber, a center panel to separate the upper and lower chambers, an inflator, and a diffuser. The lower chamber and the upper chamber may be directly inflated by the inflator, through the diffuser. The diffuser controls the amount of gas that enters each chamber, thereby during deployment, the upper chamber may have a lower internal chamber pressure relative to the internal chamber pressure of the lower chamber.

p-0026Referring to <figref idrefs="DRAWINGS">FIG. 1</figref>, an exemplary embodiment of a motor vehicle <b>20</b> is illustrated to include a multiple chamber airbag assembly <b>30</b>. The vehicle <b>20</b> is illustrated as a typical sedan, but the device of this disclosure may be used on any type of passenger vehicle as well as other moving vehicles that offer occupant protection to seated passengers in the form of frontal positioned airbags.

p-0027Referring to <figref idrefs="DRAWINGS">FIG. 2</figref>, the passenger compartment <b>21</b> of the vehicle <b>20</b> of <figref idrefs="DRAWINGS">FIG. 1</figref>, is illustrated, according to an exemplary embodiment, and includes a dashboard assembly <b>24</b>, a multiple chamber airbag assembly <b>30</b>, and a passenger seat assembly <b>22</b>. According to another exemplary embodiment, the dashboard assembly <b>24</b> may include a multiple chamber airbag assembly <b>30</b> integrated within it, and may be configured to fit within the unique packaging requirements of vehicle <b>20</b>. A multiple chamber airbag assembly <b>30</b> is flexibly configurable for use in varying package requirements, and may be tailored to satisfy specific needs of the vehicle manufacturer.

p-0028Referring to <figref idrefs="DRAWINGS">FIG. 5</figref>, an exemplary embodiment of a multiple chamber airbag assembly <b>30</b> is illustrated in the folded or non-deployed state. A multiple chamber airbag assembly <b>30</b> includes an airbag <b>34</b> and a gas generator (or inflator) <b>32</b> to provide gas to unfold and expand the airbag <b>34</b>, typically through the use of an explosive charge (e.g., pyrotechnic device). Airbag <b>34</b> may be packaged through a method of rolling and/or folding and stored within the dashboard assembly <b>24</b>. According to an exemplary embodiment, a multiple chamber airbag assembly <b>30</b> may be stored such that, during deployment, the airbag will unfold initially in a substantially upward direction, then unfold in a substantially rearward direction towards the occupant, while expanding in the cross-car and up-down directions. This embodiment typically is constructed so, during deployment, the airbag <b>34</b> will breach the upper facing surface of the dashboard assembly <b>24</b>, as shown in <figref idrefs="DRAWINGS">FIGS. 5 and 6</figref>. According to another exemplary embodiment, a multiple chamber airbag assembly <b>30</b> may be stored such that, during deployment, the airbag <b>34</b> will unfold in a substantially rearward direction towards the occupant, while expanding in the cross-car and up-down directions, similar to that shown in <figref idrefs="DRAWINGS">FIG. 4</figref>. This embodiment typically is constructed so, during deployment, the airbag <b>34</b> will breach the rear facing surface of the dashboard assembly <b>24</b> or through the door of the glove box assembly. A multiple chamber airbag assembly <b>30</b> may be packaged according to other embodiments and may deploy according to other methods and is not limited by these exemplary embodiments.

p-0029According to another embodiment, an exemplary embodiment of a multiple chamber airbag assembly <b>30</b> includes an airbag <b>34</b>, a housing <b>31</b> and a gas generator <b>32</b>. The housing <b>31</b> may be made of steel, aluminum, composite, or other useful material, and may provide structural support to the multiple chamber airbag assembly <b>30</b>, store the folded airbag <b>34</b>, and retain the gas generator <b>32</b>. The housing <b>31</b> may provide for attachment of the multiple chamber airbag assembly <b>30</b> to the vehicle <b>20</b> or to any component of vehicle <b>20</b>. The attachment may include extruded holes that accept conventional fasteners (e.g., bolts, rivets), or the attachment may be weld nuts, bolts, apertures, or other useful features to couple components.

p-0030Referring to <figref idrefs="DRAWINGS">FIG. 6</figref>, the exemplary embodiment of the multiple chamber airbag assembly <b>30</b> of <figref idrefs="DRAWINGS">FIG. 5</figref> is illustrated in the unfolded or deployed state. According to an exemplary embodiment, an airbag <b>34</b> includes a lower chamber <b>38</b>, an upper chamber <b>36</b>, and a diffusing (or center) panel <b>40</b>. The lower chamber <b>38</b> may be coupled to the housing <b>31</b> so that during deployment the gas generator <b>32</b> forces gas directly into the lower chamber <b>38</b> of the airbag <b>34</b>, expanding the lower chamber <b>38</b> as it unfolds.

p-0031According to an exemplary embodiment, diffusing panel <b>40</b> may be made of fabric or other material or film, which may be coated or uncoated, and may include a plurality of apertures that permits the transfer of gas at a predetermined pressure. According to other exemplary embodiments, diffusing panels <b>40</b> may diffuse gas through the mesh structure of the fabric or material from which the diffusing panel <b>40</b> is constructed. A center panel <b>40</b> may be constructed to diffuse gas at a predetermined rate based on a predetermined pressure to optimize performance of the safety system. During deployment of airbag assembly <b>30</b>, when the internal pressure of the lower chamber <b>38</b> reaches a predetermined pressure, gas begins to diffuse through the diffusing panel <b>40</b> into the upper chamber <b>36</b> of airbag <b>34</b>, expanding and unfolding the upper chamber <b>36</b>. Therefore the upper chamber <b>36</b>, as shown in <figref idrefs="DRAWINGS">FIG. 6</figref>, may be indirectly inflated by the gas generator <b>32</b>. This configuration has multiple chambers, with each chamber having a varying internal chamber pressure. According to the exemplary embodiment of <figref idrefs="DRAWINGS">FIG. 6</figref>, the upper chamber <b>36</b> may have a lower internal chamber pressure relative to the internal chamber pressure of the lower chamber <b>38</b>, whereby the upper chamber <b>36</b> provides support to the head and neck regions of the occupant and the lower chamber <b>38</b> provides support to the torso region of the occupant. This configuration optimizes protection to the occupant by exerting less restraint force onto the lower mass head and neck of the occupant and exerting more restraint force onto the higher mass torso of the occupant. This optimized protection reduces the likelihood of an injury to the occupant, especially to the head and neck of the occupant.

p-0032According to other embodiments, multiple chamber airbag assemblies may be configured to include any number of directly or indirectly inflated with each indirectly inflated chamber separated from a directly inflated chamber by a diffusing panel. Each diffusing panel may be constructed to provide different transfer rates for the inflation gas, to control the expansion of that specific chamber and to further control the internal pressure of that specific chamber to provide a predetermined restraint force onto the occupant. Therefore a multiple chamber airbag assembly may be tailored to have a plurality of chambers, each having a predetermined internal pressure at deployment to provide optimized occupant protection during a vehicle impact event that triggers deployment. According to other exemplary embodiments, multiple chamber airbag assemblies may have more than one chamber being directly inflated by the gas generator and having at least one other chamber indirectly inflated through a diffusing panel.

p-0033A diffusing panel <b>40</b> may be constructed to form a geometry, upon deployment, that includes a combination of concave and convex portions <b>41</b>, <b>42</b>, with respect to the lower chamber <b>38</b>. According to an exemplary embodiment, diffusing panel <b>40</b> of airbag assembly <b>30</b>, when deployed, includes a first convex portion <b>42</b>, a second convex portion <b>42</b>, and a concave portion <b>41</b>, which is positioned between the first and second convex portions <b>42</b> in the fore-aft direction of vehicle <b>20</b>. This configuration of diffusing panel <b>40</b> provides improved stability of airbag assembly <b>30</b> during deployment, by having less bounce relative to multiple chamber airbags that include a substantially flat center panel. The configuration of diffusing panel <b>40</b> disclosed in this application produces less bounce by directing inflation gas (and hence forces generated by the inflation gas) from the lower chamber <b>38</b> into the upper chamber <b>36</b> along vectors that are substantially horizontal or diagonal in addition to substantially vertical, where a flat diffusing panel directs gas along only substantially vertical vectors. The substantially vertical forces generated by a flat diffusing panel create a greater tendency for the airbag to bounce, during deployment, due to the offset distance between the fixed portion of the airbag, which is coupled to the housing, and the diffusing location which varies along the length of the center panel. These vertical diffusing forces generate a series of moments from each offset distance that induces the airbag to bounce, typically between the dashboard and windshield of the vehicle. The airbag assembly <b>30</b> constructed with a diffusing panel <b>40</b> that includes a series of concave and convex portions <b>41</b>, <b>42</b>, directs more gas along substantially horizontal and diagonal vectors, reducing bounce. This configuration also has less volume that is directly injected between the windshield <b>26</b> and dashboard <b>24</b>, which additionally reduces bounce.

p-0034According to other embodiments, airbag assemblies may be configured to include center panels, which include any combination of concave and convex portions and is not limited to the exemplary embodiment above. Additionally, center panels may further be configured to reduce vertical forces resulting from inflation of the upper chamber from the lower chamber through the center panel, by restricting gas flow through the substantially vertical facing portions and/or by increasing gas flow through the substantially horizontal facing portions.

p-0035Additionally, the multiple chamber airbag assembly also may be configured with a lower mass gas generator than traditionally configured airbags. Typically, one of the key parameters in designing the size of the gas generator required is the volume of the airbag that is to be directly inflated. The multiple chamber airbag assemblies disclosed may have a reduced volume being directly inflated, allowing for a smaller mass and cost gas generator to be used in constructing the multiple chamber airbag assemblies.

p-0036Referring to <figref idrefs="DRAWINGS">FIG. 7</figref>, another exemplary embodiment of a multiple chamber airbag assembly <b>130</b> is illustrated in the unfolded or deployed state, and includes a housing <b>31</b>, an airbag <b>134</b>, a gas generator <b>32</b>, and at least one tether <b>50</b>. Airbag <b>134</b> includes at least one chamber, such as lower chamber <b>38</b>, which is directly inflated by the gas generator <b>32</b>; at least one chamber, such as upper chamber <b>36</b>, which is indirectly inflated by the gas generator <b>32</b>; and at least one diffusing panel <b>40</b>, which separates an indirectly inflated chamber from a directly inflated chamber. Diffusing panel <b>40</b>, when deployed, forms two convex portions <b>142</b> with a concave portion <b>141</b> between them. The tethers <b>50</b>, as shown in <figref idrefs="DRAWINGS">FIG. 7</figref>, extend in a substantially vertical direction. According to other embodiments, tethers <b>50</b> may be configured to extend in a substantially horizontal direction, a substantially diagonal direction, or any other useful direction. The tethers <b>50</b> provide support to the airbag <b>134</b> during deployment to tailor the trajectory or shape of the airbag <b>134</b>, to further improve occupant protection to further reduce occupant injury during a dynamic vehicle impact event.

p-0037Referring to <figref idrefs="DRAWINGS">FIGS. 8 and 9</figref>, another exemplary embodiment of a multiple chamber airbag assembly <b>230</b> is illustrated in the unfolded or deployed state, and includes a housing <b>231</b>, an inflator <b>232</b>, an airbag <b>234</b>, and an airbag ring <b>244</b>. Airbag <b>234</b> includes a lower chamber <b>238</b> and an upper chamber <b>236</b>, which are separated by a center panel <b>240</b>. Center panel <b>240</b>, when deployed, forms two convex portions <b>242</b> with a concave portion <b>241</b> between the two convex portions <b>242</b>. Center panel <b>240</b> may be coupled to the airbag ring <b>244</b> to tailor the amount of gas injected into each chamber.

p-0038Airbag ring <b>244</b> may be made of steel or other material that may withstand the high temperatures and pressures generated by the creation and dispersion of the inflation gas. Airbag ring <b>244</b> includes a first cavity <b>245</b> and a second cavity <b>246</b> separated by a wall or divider, which may be coupled to the center panel <b>240</b>. The first cavity <b>245</b> of airbag ring <b>244</b> serves as the inlet for inflation gas that directly inflates the lower chamber <b>238</b> of airbag <b>234</b>, and the second cavity <b>246</b> of airbag ring <b>244</b> serves as the inlet for inflation gas that directly inflates the upper chamber <b>236</b> of airbag <b>234</b>. The first and second cavities <b>245</b>, <b>246</b> of airbag ring <b>244</b> may include apertures to allow inflation gas to flow through. According to an exemplary embodiment, the apertures of the first cavity <b>245</b> allow more inflation gas to pass through than the apertures of the second cavity <b>246</b> to create a higher internal chamber pressure within the lower chamber <b>238</b> than within the upper chamber <b>236</b>. The pressures of the different airbag chambers <b>236</b>, <b>238</b> may be tailored by the specific configurations of the apertures of the airbag ring cavities <b>245</b>, <b>246</b>. For example, the airbag ring first cavity <b>245</b> may have larger or more apertures, when compared to the apertures of the airbag ring second cavity <b>246</b>, thereby allowing more volume of inflation gas to pass through per second.

p-0039Referring to <figref idrefs="DRAWINGS">FIG. 10</figref>, an exemplary embodiment of an airbag ring <b>44</b> is illustrated coupled to an airbag housing <b>31</b>, which together encompass the inflator <b>32</b>. This configuration may be used in construction of a multiple chamber airbag assembly, such as the multiple chamber airbag assembly <b>30</b>, as shown in <figref idrefs="DRAWINGS">FIG. 6</figref>. Airbag ring <b>44</b> includes a single cavity, which includes apertures that allow inflation gas to pass through, upon deployment of the airbag assembly <b>30</b>.

p-0040Referring to <figref idrefs="DRAWINGS">FIG. 11</figref>, another exemplary embodiment of a multiple chamber airbag assembly <b>330</b> is illustrated and includes a housing <b>331</b>, first and second inflators <b>332</b>, <b>333</b> that are coupled to the housing <b>331</b>, and an airbag <b>334</b>. Airbag <b>334</b> includes a lower chamber <b>338</b>, an upper chamber <b>336</b>, and a center panel <b>340</b>, which separates the lower and upper chambers <b>338</b>, <b>336</b>. A first inflator <b>332</b>, upon actuation, deploys inflation gas which may directly inflate the lower chamber <b>338</b> of airbag <b>334</b>. A second inflator <b>333</b>, upon actuation, deploys inflation gas which may directly inflate the upper chamber <b>336</b> of airbag <b>334</b>. Upon deployment of airbag <b>334</b>, center panel <b>340</b> forms a combination of convex and concave portions <b>342</b>, <b>341</b> with respect to the lower chamber <b>338</b>. First inflator <b>332</b> may be configured to be more powerful (i.e., produce more inflation gas inducing higher inflation pressure) that the second inflator <b>333</b>, thereby upon deployment, lower chamber <b>338</b> may have a higher internal chamber pressure relative to the upper chamber <b>336</b>.

p-0041Referring to <figref idrefs="DRAWINGS">FIG. 12</figref>, another exemplary embodiment of a multiple chamber airbag assembly <b>430</b> is illustrated and includes a housing <b>431</b>, an inflator <b>432</b>, an airbag <b>434</b>, and a diffuser <b>447</b>. Airbag <b>434</b> includes a lower chamber <b>438</b>, an upper chamber <b>436</b>, and a center panel <b>440</b>, which separates the lower and upper chambers <b>438</b>, <b>436</b>. Center panel <b>440</b> may be coupled to diffuser <b>447</b>, and upon deployment of airbag <b>434</b>, center panel <b>440</b> forms a combination of convex and concave portions <b>442</b>, <b>441</b> with respect to the lower chamber <b>438</b>. Diffuser <b>447</b> may be coupled to airbag <b>434</b>, and upon actuation of inflator <b>432</b> may direct more inflation gas into the lower chamber <b>438</b> than the upper chamber <b>436</b>, thereby inducing a higher internal pressure within lower chamber <b>438</b> relative to upper chamber <b>436</b>.

p-0042According to an exemplary embodiment, diffuser <b>447</b> may be made of a cloth or fabric which allows inflation gas to pass through it. According to other embodiments, diffuser <b>447</b> may be made from a polymer, composite material, or other useful material. Diffuser <b>447</b> may be coated or uncoated, and may contain apertures, voids or other useful features to allow gas to pass through it.

p-0043Referring to <figref idrefs="DRAWINGS">FIG. 13</figref>, a portion of another exemplary embodiment of an airbag <b>534</b> is illustrated and includes a lower chamber <b>538</b>, an upper chamber <b>536</b> (not shown for clarity), and a center panel <b>540</b>, which separates the upper and lower chambers <b>536</b>, <b>538</b>. The center panel <b>540</b> is coupled to both the upper and lower chambers <b>536</b>, <b>538</b> through stitching, and upon deployment forms two convex portions <b>542</b> separated by a concave portion <b>541</b>. The lower chamber <b>538</b> includes an opening at one end to allow inflation gas to enter the chamber and unfold it during deployment. According to an exemplary embodiment, the stitching which couples the center panel <b>540</b> to the chambers includes gaps (or voids) <b>548</b>, which allow inflation gas to pass by the center panel <b>540</b> from the lower chamber <b>538</b> into the upper chamber <b>536</b>. The quantity and size (e.g., length and width) of voids <b>548</b> drive the amount of inflation gas that passes from the lower chamber <b>538</b> into the upper chamber <b>536</b>, and may be varied or tailored to specific applications. It should be noted that this configuration could be combined with other configurations, for example, a configuration with a center panel including apertures to further influence the transfer of inflation gas from the lower chamber to the upper chamber.

p-0044As utilized herein, the terms “approximately,” “about,” “substantially”, and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims.

p-0045It should be noted that the term “exemplary” as used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representations, and/or illustrations of possible embodiments (and such term is not intended to connote that such embodiments are necessarily extraordinary or superlative examples).

p-0046The terms “coupled,” “connected,” and the like as used herein mean the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another.

p-0047References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below,” etc.) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.

p-0048It is important to note that the construction and arrangement of the multiple chamber airbag system as shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present invention.